Space frames for vehicles are generally known and are typically found in vehicles intended for use in off-road driving (e.g., "dune buggies" and "all-terrain vehicles") or racing.
Space frames may include a roll cage to provide strength to the frame and protection for the occupants in the event of a roll-over. A space frame for an off-road vehicle typically includes a roll cage since off-road driving ordinarily subjects the frame to severe loads due to the sudden impacts upon the vehicle caused, for example, by striking hard objects such as boulders, trees and mounds, by traveling over uneven terrain, and by falling into holes. Such impacts may further stress the vehicle frame (such as by twisting) by being unbalanced relative to the frame (for example, the load on only one of the front corners produced by one of the front tires impacting a large rock).
The weight of the space frame is also a primary consideration. A space frame is ordinarily desired to be as light as possible to increase the speed, agility and fuel economy of the vehicle, and decrease the material cost of the space frame. On the one hand, large members are typically stronger than small members and, as discussed above, the strength of the frame is of paramount importance.
In addition, where the vehicle is intended for military application, greater mobility, higher speeds, low weight and low profile become quite important. Of equal importance in this capacity is the payload to curbweight ratio, which is desired to be as high as possible. In most vehicles the ratio is in the order of 0.3:1. For military applications, which often require high payloads, the ratio should be considerably higher. Advantageously, the payload to curbweight ratio should be about 0.75:1 to 1:1 or even higher.
These advantages, especially those related to the military application requirements are provided by the triangulated tubular space frame for a low profile, light truck with foldable rollbars where the triangulation elements of the space frame are substantially, if not entirely, below the tub or floor according to the present invention as described in more detail below.